Basic HTML version of Foils prepared April 7 1998

Foil 27 Introduction to Cryptography

From Basic Principles of Java and Internet Security CPS616 Web Technologies -- Spring 98. by Geoffrey C. Fox
1 This is old technology first attributed to Julius Caesar who used the nifty cipher which replaced every latter with that three letters further in the alphabet
  • So A becomes D and Z becomes C (using cyclic wraparound)
2 Most ciphers involve an algorithm and a parameter (this is 3 in the above) where usually algorithm can be public but parameter is kept secret and is called a key
  • key needs to be quite big to be safe (say at least 40 bits long)
  • It is usually not possible to keep algorithm secret and in fact making it public can encourage experts to examine and comment on its reliability (I.e. ease of breaking)
in Table To:

© Northeast Parallel Architectures Center, Syracuse University, npac@npac.syr.edu

If you have any comments about this server, send e-mail to webmaster@npac.syr.edu.

Page produced by wwwfoil on Mon Apr 6 1998